Weighing apparatus

ABSTRACT

A weighing apparatus for relatively bulky food, or the like, in which the material is conveyed in excess of a unit quantity to a dual conveyor system carried by a scale, the material is weighed and the electronically controlled conveyors discharge the desired quantity of the material into a collecting hopper.

United States Patent Stambera 1 Mar. 19, 1974 1 WEiGHING APPARATUS2.867.246 1/1959 Busse 141/115 3.494.507 2/1970 Ricciardi 198/39 [75]lnvemor- Adlf slambera, Stuttgart Germany 2.662.665 12/1953 Harper198/39 [73] Assignee: Fr. Hesser Maschinenfabrik AG,

St tt tu gar Bad Cannstatt Germany Primary ExaminerR1chard E. AegerterFiledl 1971 Assislant E.raminer-Joseph E. Valenza Appl. No: 207,331

[57] ABSTRACT A weighing apparatus for relatively bulky food, or thelike, in which the material is conveyed in excess of a unit quantity toa dual conveyor system carried by a scale, the material is weighed andthe electronically controlled conveyors discharge the desired quantityof the material into a collecting hopper.

4 Claims, 3 Drawing Figures I Lllllh PAIENTEDMAR 19 1914 Y 3; 797.633

SHEET 1 BF 2 WEIGHING APPARATUS The invention relates generally to aweighing apparatus for use in conjunction with automatic packagingsystems, and more particularly, for weighing predetermined quantities ofpiece goods, such as biscuits orthe like.

In the prior art, weighing devices of this type are already known, e.g.,see German DAS 1,549,191, in which a weighing receptacle is associatedwith a scale and the latter controls a metering device in conjunctionwith a calculator. A conveyor is associated with the weighingreceptacle, with its operation controlled by the calculating machine, soas to remore the bulk material already weighed from the weighingreceptacle and place it into a collecting receptacle. The device alsohas a provision for a coarse and a fine conveyor belt for dischargingthe bulk material, so that most of the material in the weighingreceptacle can be rapidly conveyed out of it. This weighing device,however, is not suitable in this form for weighing out products likebiscuits, candies, or the like which are in relatively large form, sincein this application, as in other weighing systems, difficulties arise inseparating the individual pieces'when a predetermined quantity has to beweighed.

It is therefore the primary object of the present invention to provide aweighing apparatus which is adapted to specifically weigh predeterminedquantities of relatively large piece goods such as candy or biscuits andto obviate difficulties encountered in the past in accurately weightingsuch goods.

In order to solve the problem of weighing products of the type describedabove, it is proposed, in accordance with the present invention, toprovide a weighing device in which a quantity of the goods having aweight in excess of the predetermined weight is placed in a weighingreceptacle, connected to a scale, in which the receptacle comprises twoconveyor belts arranged at right angles to and vertically above eachother.

A more specific aspect of the present invention resides in that theupper conveyor belt terminates above the lower belt so that any materialconveyed on the upper belt falls onto the lower belt. This effects thatthe material on the upper belt is initially detoured in its path fromthe weighing receptacle onto the lower belt. However, when the goodspass from the one belt to the other, the individual pieces becomeseparated from each other as desired, thus improving the accuracy of theweighing operation. I

Another aspect of the present invention provides a weighing device inwhich the upper conveyor belt has an overflow edge extending,essentially, in the direction of conveyor travel. This ensures that thegoods on the upper belt do not exceed, or exceed only slightly, anoptimum height which allows the pieces to fall individ ually, while theedge provides ample storage capacity on the belt to sustain a regulateddischarge flow. Any of the goods passing over the overflow edge to thelower conveyor belt may then be removed from the weighing receptacle asquickly as desired.

For a better understanding of the present invention, together with otherand further objects thereof, reference is had to the followingdescription taken in connection with the accompanying drawings, and itsscope will be pointed out in the appended claims.

In the drawings:

FIG. 1 is a plan view of the weighing device according to the invention;

FIG. 2 is a side elevational view of the device shown in FIG. 1; and

FIG. 3 is a front elevational view of the devices shown in FIGS. I and2x Referring now specifically to the drawings, there is shown twoweighing devices 1,2 arranged side-by-side in a mirror image, and areadapted to receive the goods to be weighed from a common storagereceptacle 5 by means of feed channels 3,4 which are also arranged in amirror image. Each of the feed channels has its own drive 6 such as, forexample, an electromagnetic drive.

Each of the two weighing devices operate inthe same manner; therefore,for simplicity of description, only one will hereafter be described indetail.

The weighing device 1 comprises a scale 7, of a type known per se,carrying. a weighing receptacle 8 which includes two conveyor belts 9,10 arranged at right angles to and vertically above each other. Themovement of the conveyor belts 9, 10 is controlled by the scale 7through the operation of a conventional electronic weight control unit1 1. The device also includes a loading weight 12 which can be raisedand lowered in a controlled manner by means of a lifting device 13, insuch a manner that it may be suspended from a hook 14 of the weighingreceptacle 8 and may thus be used to load scale 7.

The conveyor belts 9,10 are driven by motors, not shown. The upper belt9 preferably terminates at an end above the lower belt 10 in such amanner that the goods leaving the upper belt fall onto the lower belt.The latter belt terminates above a collecting hopper 15 which serves tofill the weighed material into packaging containers, not shown.

The piece goods are weighed out as follows. The loading weight 12 israised and feed channel 3 is switched on to bring material from storagereceptacle 5 to both conveyor bels 9,10. The feed channel 3 is switchedoff as soon as scale 7 indicates on control unit 1 1 a load greater thana predetermined nominal weight on the belts. After feed channel 3 hasbeen switched off, the last reading on scale 7 is stored in control unit11. A table 16 in lifting device 13 is then lowered, so that loadingweight 12 descends onto hook l4 and loads scale 7. The loading weight 12is exactly the same weight as the predetermined unit weight of materialto be weighed. With scale 7 additionally loaded in this manner, conveyorbelts 9,10 are switched on and the material thereon begins to pass tocollecting hopper 15. This reduces the total load on scale 7 and thisreduced weight is signalled to control unit 11. This value, whichdecreases more or less rapidly, is constantly compared with the valuestored in control unit 1 1 immediately before weight 12 was hooked up.As soon as the two values are the same, conveyor belts 9,10 are stoppedand the weighing of one lot or unit is thus completed.

As soon as loading weight 12 is raised, weighing receptacle 8 is readyto accept a new lot of material to be weighed.

As a result of the relative positioning of conveyor belts 9,10, asdescribed above, the flow stream of material when conveyor belts 9,10are switched on for the first phase is relatively powerful and coarse,whereas when the belts are switched on for the second phase, the flow ofthe material out of weighing receptacle 8 is a very fine stream whichimproves the accuracy of the weighing operation. If necessary, therelationship between these coarse and fine (trickle) flow streams mayvalso be adjusted in known fashion by changing the speeds at which thematerial is conveyed.

Uniformity of the coarse and fine flow streams, in accordance with theproperties of the material being weighed, may be obtained by imparting,at least to the upper conveyor belt, an upward or a downward slope. Theoverlap between the two belts may also be adjusted for the same purpose.

Another possible arrangement of the two conveyor belts is to tilt theupper conveyor belt 9 at right angles to its direction of travel, and toarrange along the lower side of the inclined plane of the belt a guidewall 17, which preferably is adjustable in height. The material arrivingfrom feed channel 3 and falling onto upper belt 9 forms a storage layerof the desired thickness and any excess material falling over overflowedge 18 of wall 17 falls onto lower conveyor belt 10. From belt 10 theoverflow material travels over a short path during the weighingoperation, and therefore quickly, to collecting hopper 15. In thistilted arrangement, the lower belt 10 may be relatively wide and short,while the upper belt may be relatively long, so that it can shakematerial off laterally onto the lower belt. Thus, even if lower belt 10travels relatively slowly, the material thereon can be quickly carriedaway. Although this arrangement has very high output capacity, it may beused, however, with advantage only if an adequately fine and uniformfine-flow stream can be produced even when the material is not detouredover lower conveyor belt 10.

While there have been described what are at present considered to be thepreferred embodiments of this invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madeWhat is claimed is: j l. Weighing apparatus for weighing discreteamounts of bulky particulate materials, in which such materials areconveyed to a receptacle in a quantity exceeding the predetermined unitweight, are weighed by a scale and thereafter the desired predeterminedquantity is discharged from the receptacle controlled by the scale intoa receiving unit, comprising:

a material feed channel; a weighing receptacle placed for receiving saidmaterials to be weighed, said receptacle being formed of a dual conveyorbelt system with one conveyor spaced vertically above and at right angleto the other conveyor for discharging said materials from the upper ontothe lower conveyor, said upper conveyor belt also being disposed atright angle to the direction of travel of the material in said feedchannel; whereby the particulates are separated by movement and fallfrom one conveyor to the other;

a scale placed below said weighing receptacle and carrying the latter toweigh any material on the receptacle as a single unit;

and electronic control means operatively associate with said scale andsaid weighing receptacle including means effective to halt the movementof the conveyor belts when said conveyor belts have discharged saidpredetermined quantity into the receiving unit.

2. A weighing apparatus according to claim 1, in which at least theupper conveyor is inclined in the direction of the conveyor travel.

3. A weighing apparatus according to claim 1, and loading weight meansfor placing an additional weight upon said scale corresponding to thedesired weight.

4. A weighing apparatus according to claim 1, wherein the direction oftravel of the upper belt is substantially perpendicular to the directionof travel of the lower belt.

1. Weighing apparatus for weighing discrete amounts of bulky particulatematerials, in which such materials are conveyed to a receptacle in aquantity exceeding the predetermined unit weight, are weighed by a scaleand thereafter the desired predetermined quantity is discharged from thereceptacle controlled by the scale into a receiving unit, comprising: amaterial feed channel; a weighing receptacle placed for receiving saidmaterials to be weighed, said receptacle being formed of a dual conveyorbelt system with one conveyor spaced vertically above and at right angleto the other conveyor for discharging said materials from the upper ontothe lower conveyor, said upper conveyor belt also being disposed atright angle to the direction of travel of the material in said feedchannel; whereby the particulates are separated by movement and fallfrom one conveyor to the other; a scale placed below said weighingreceptacle and carrying the latter to weigh any material on thereceptacle as a single unit; and electronic control means operativelyassociated with said scale and said weighing receptacle including meanseffective to halt the movement of the conveyor belts when said conveyorbelts have discharged said predetermined quantity into the receivingunit.
 2. A weighing apparatus according to claim 1, in which at leastthe upper conveyor is inclined in the direction of the conveyor travel.3. A weighing apparatus according to claim 1, and loading weight meansfor placing an additional weight upon said scale corresponding to thedesired weight.
 4. A weighing apparatus according to claim 1, whereinthe direction of travel of the upper belt is substantially perpendicularto the direction of travel of the lower belt.